Go Back  RCU Forums > Electric Aircraft Universe > Electric RC Jets
 Tail Tube for 90mm ducted fan >

Tail Tube for 90mm ducted fan

Notices
Electric RC Jets Discuss rc electric ducted fan or radio control prop jets here.

Tail Tube for 90mm ducted fan

Old 06-13-2012, 09:33 AM
  #1  
Thread Starter
My Feedback: (11)
 
Join Date: Jun 2009
Location: Maryland, MD
Posts: 1,399
Received 3 Likes on 3 Posts
Default Tail Tube for 90mm ducted fan

I have a friend looking for a tail tube (exhaust) for a 90mm ducted fan Ideally it would taper from 90 to 80mm and be around 12in long.

Is this something we can guy somewhere or are we going to have to fabricate it? If we can purchase, can you please name a supplier?

Thanks for your responses.
Old 06-13-2012, 12:44 PM
  #2  
Moderator
My Feedback: (1)
 
AMA 74894's Avatar
 
Join Date: Jun 2002
Location: Spicer, MN
Posts: 1,216
Likes: 0
Received 4 Likes on 4 Posts
Default RE: Tail Tube for 90mm ducted fan

http://www.officemax.com/office-supp...oduct-ARS25667

make one end 95mm, the other end make 85mm (5 mm for overlap)
HobbyKing also has the material.. for a whopping $1.99
http://www.hobbyking.com/hobbyking/s...C_1_Metre.html

Not to plug HK or anything, (I was also looking for specific instructions) the 4th post down has step by step instructions...
http://www.hobbyking.com/hobbyking/f....asp?TID=22007

hope it helps!
Old 06-13-2012, 01:44 PM
  #3  
My Feedback: (9)
 
juanjulian's Avatar
 
Join Date: Nov 2003
Location: guatemala, GUATEMALA
Posts: 544
Likes: 0
Received 1 Like on 1 Post
Default RE: Tail Tube for 90mm ducted fan


The taper of 80-85 mm is to big.

Go from 72 to 75 mm

Cheers,

Juan
Old 06-14-2012, 02:28 AM
  #4  
Thread Starter
My Feedback: (11)
 
Join Date: Jun 2009
Location: Maryland, MD
Posts: 1,399
Received 3 Likes on 3 Posts
Default RE: Tail Tube for 90mm ducted fan

So what you are really saying is that it can be flown without an exhaust tube.
Old 06-14-2012, 05:33 AM
  #5  
Moderator
My Feedback: (1)
 
AMA 74894's Avatar
 
Join Date: Jun 2002
Location: Spicer, MN
Posts: 1,216
Likes: 0
Received 4 Likes on 4 Posts
Default RE: Tail Tube for 90mm ducted fan

it should be able to be flown without it. the thrust tube is something typically used to gain better performance from the EDF unit, but in some cases (typically for bigger / more complicated jets) it can be used to keep things (like elevator servo leads) from causing turbulence in the exhaust.
TYPICALLY, (for an EDF) the thrust tube is optional.
what airplane we talking about?
Old 06-15-2012, 05:58 AM
  #6  
Thread Starter
My Feedback: (11)
 
Join Date: Jun 2009
Location: Maryland, MD
Posts: 1,399
Received 3 Likes on 3 Posts
Default RE: Tail Tube for 90mm ducted fan

Red Hawk 90mm Ducted fan Jet.
Old 06-20-2012, 05:51 PM
  #7  
 
speed is life's Avatar
 
Join Date: May 2006
Location: Redstone, CO, USA
Posts: 390
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan


ORIGINAL: AMA 74894
.............TYPICALLY, (for an EDF) the thrust tube is optional........
Not true, a "typical" EDF will not perform well at all without a thrust tube, unless you are talking about little depron profile types.

Tubes can (as mentioned above) be simply made using rolled Mylar drafting film. You want the exhaust to be about 85% to as small as 80% of Fan Swept Area.
Good WAG for a 90mm fan is 70-75mm outlet

Mike Warren
www.performance-edf.biz

<br type="_moz" />
Old 06-28-2012, 01:58 PM
  #8  
My Feedback: (23)
 
Join Date: Dec 2004
Location: mt dora, FL
Posts: 518
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan

buy yourself some mylar. a roll is nice to have to experiment with
Old 08-03-2012, 01:53 PM
  #9  
Junior Member
 
Join Date: Aug 2012
Location: boston, UNITED KINGDOM
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan

so say you have an 100mm fan then with say 100mm going in to fan what should the out be at end of fusalage ? Neil
Old 08-03-2012, 02:09 PM
  #10  
 
speed is life's Avatar
 
Join Date: May 2006
Location: Redstone, CO, USA
Posts: 390
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan


ORIGINAL: tinker27

so say you have an 100mm fan then with say 100mm going in to fan what should the out be at end of fusalage ? Neil
That depends on what fan you have, each is different as to "FSA" ......(Fan Swept Area - area of the circle covered by the blades MINUS the area covered by the outer diameter of the motor holder)
Typically you set the exhaust "area" at 80-90% of "FSA", work backwards from the area to derive the required diameter of the exhaust.
A decent place to start is 85% FSA

This number can also be dependent of how much intake area you actually have to feed the fan,If you had tight intakes then you don't want the exhaust area to be greater than intake area........no matter what the FSA calculation tells you it would require tightening up the exhaust for decent performance.

-Mike
<br type="_moz" />
Old 08-03-2012, 02:23 PM
  #11  
Junior Member
 
Join Date: Aug 2012
Location: boston, UNITED KINGDOM
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan

well im gonna use a stumax 100-45 mm in a AMD hawk so any ideas speed is life ? thanks Neil
Old 08-03-2012, 03:59 PM
  #12  
 
speed is life's Avatar
 
Join Date: May 2006
Location: Redstone, CO, USA
Posts: 390
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan


ORIGINAL: tinker27

well im gonna use a stumax 100-45 mm in a AMD hawk so any ideas speed is life ? thanks Neil
Just measure your fan and do the maths.......or there are online area and circle calculators.
Im out at work or I could measure the 100-45

80mm exhaust will get you close.
The 100-45 will be a nice lighter (but powerful) alternative to the 120-127mm diameter fans

-Mike
www.performance-edf.biz
<br type="_moz" />
Old 08-04-2012, 10:52 AM
  #13  
Junior Member
 
Join Date: Aug 2012
Location: boston, UNITED KINGDOM
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Tail Tube for 90mm ducted fan

Thanks mike will do , regaurds Neil
Old 01-03-2016, 08:52 AM
  #14  
Junior Member
My Feedback: (4)
 
Join Date: Jul 2005
Location: Augusta, KS
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Ok, guys, Answer this question for me please..I have a 90 mm ducted fan F-86. When the fan and motor were installed, the installer cracked the thrust tube where the wiring for the motor passes thru it..It was done without much care..What I want to know is if I can smoothe it out and just install a four to six inch section of mylar or whatever is used for thrust tubes, to repair just this area..Just to smooth it out....I can not remove the existing cracked tube...Any better Ideas out there..Thanks, And fire some ideas at me..

Well I fired this jet up and it just blew the thrust tube into pieces and out the tail pipe, so now need to fab and install a new tube....

Last edited by airrds; 01-09-2016 at 06:32 AM.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.